Messages in this thread | | | Subject | Re: Does it need to implement irq_set_type method in the ioapic_chip? | From | "H. Peter Anvin" <> | Date | Tue, 18 Feb 2014 18:34:38 -0800 |
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This is an ACPI device connecting to an internal IOAPIC? If not, how is it connected?
On February 18, 2014 6:32:44 PM PST, carl peng <carlpeng008@gmail.com> wrote: >Hi Thomas, > >Thanks a lot for your help! > >But I still have some confusion. Could you please help to give some >suggestions to me? > >1) This device is a ACPI device, the hardware engineer designed it as >falling edge interrupt trigger >mode, does it need to re-work the hardware and modify it as rising >edge trigger mode to suit the >Linux APIC driver architecture? >2) Why does APIC driver not implement the irq_set_type method? if >implement it, will supply more >free space for the device driver developer(they can set the interrupt >trigger mode by calling request_irq). > >Thank you! >Carl > > >On Wed, Feb 19, 2014 at 4:13 AM, Thomas Gleixner <tglx@linutronix.de> >wrote: >> On Tue, 18 Feb 2014, carl peng wrote: >> >> Carl, sending the same mail twice within an hour does not speed up >> things. It's quite likely that it gets ignored. >> >>> 1. Does it need to implement irq_set_type method in the ioapic_chip >>> structure? >> >> No. The irq type is configured by the type of the interrupt or the >> BIOS. >> >> ISA interrupts are always polarity zero edge triggered (historic) >> >> PCI interrupts are always polarity one level triggered >> >> PCIE interrupts are either legacy PCI or with MSI[X] always edge >> triggered >> >>> 2. if no need to implement it, how can device driver set the trigger >mode >>> of APIC interrupt controller pin? >> >> Not at all. >> >> The device which is connected to one of the busses must follow the >> specification of the bus. There is no choice. Any additional >> requirements of the device to deal with external signals must be >> handled by the device itself and converted to the appropriate bus >> requirement. >> >> This all is configured by the kernel automatically through bus >> detection and BIOS tables. >> >> Thanks, >> >> tglx
-- Sent from my mobile phone. Please pardon brevity and lack of formatting.
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